Design and test of laser wind measurement system for yaw control of wind turbine

In order to measure the incoming wind information before it reaches a wind turbine, a laser wind measurement system was developed for need of yaw control of wind turbine based on continuous wave coherence detection. A direct drive(DD) motor was installed in the scanner to drive a wedge lens with 15° vertex angle for laser conical scanning in the atmosphere. The scan period is 15 s, and has 30 sampling points. The sinusoidal fitting method was used to retrieve the velocity and direction of the incoming wind field of wind turbine. The laser wind measurement system was installed under the meteorological gradient observation tower in Shenzhen, and a comparative experiment was carried out with the ultrasonic anemometer on the tower. Measured data were compared and the results are as follows: the correlation coefficient of horizontal wind speed was 0.98 and the standard deviation was 0.22 m/s, the correlation coefficient of wind direction data was 0.97 and the standard deviation was 3.04°. It shows that the laser wind measurement system has satisfactory performance and can provide accurate parameters of wind turbine, which is conducive to improve the efficiency of wind energy utilization.